A resin composition based on a polyphenylene ether (hereinafter referred to as “PPE”)-based resin has characteristics such as thermal resistance, electrical properties, size stability, impact resistance, low specific gravity or the like, and can be made flame retardant without use of halogen compound or antimony compound that places a heavy burden on the environment, and thus is used in a wide range of applications such as various electric/electronic components, office appliance parts, automobile parts, building materials, other various exterior materials, industrial supplies or the like.
In recent years, in addition to short-term properties, long-term properties are also required to achieve miniaturization and high performance, and maintenance of mechanical strength and retention of flame retardancy when placed under high temperature environment over a long period of time are also required for polyphenylene ether-based resin composition.
As a method of increasing the thermal stability of the polyphenylene ether developed so far, a technique in which a specific hydrogenated block copolymer and a specific flame retardant are added at a specific ratio and further a specific production method is used (see JP5704936 B2 (PTL1)), and a technique in which a polyphenylene ether terminal is stabilized by adding a vinyl compound (see JP2925646 B2 (PTL2)) or the like are known.